SWMenu is a menu-driven interface for the Portland combined sewer overflow (CSO) modeling system that is based on the US EPA Stormwater Management Model (SWMM). The interface provides automation of SWMM model runs, relational database functions, generation of SWMM input data files, tabular and graphical output of SWMM runs, and specific features and utilities developed during two years of simulating the Portland system for CSO faculties planning. The name “SWMenu” was chosen to clarify that the program is a menu-driven graphical interface as opposed to a GIS-type graphical interface.